<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!-- saved from url=(0035)http://fgm.cc/learn/lesson8/03.html -->
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>窗口拖拽（改变大小/最小化/最大化/还原/关闭）</title>
<style type="text/css">
body,div,h2{margin:0;padding:0;}
body{background:url(img/bg.jpg);font:12px/1.5 \5fae\8f6f\96c5\9ed1;color:#333;}
#drag{position:absolute;top:100px;left:100px;width:300px;height:160px;background:#e9e9e9;border:1px solid #444;border-radius:5px;box-shadow:0 1px 3px 2px #666;}
#drag .title{position:relative;height:27px;margin:5px;}
#drag .title h2{font-size:14px;height:27px;line-height:24px;border-bottom:1px solid #A1B4B0;}
#drag .title div{position:absolute;height:19px;top:2px;right:0;}
#drag .title a,a.open{float:left;width:21px;height:19px;display:block;margin-left:5px;background:url(img/tool.png) no-repeat;}
a.open{position:absolute;top:10px;left:50%;margin-left:-10px;background-position:0 0;}
a.open:hover{background-position:0 -29px;}
#drag .title a.min{background-position:-29px 0;}
#drag .title a.min:hover{background-position:-29px -29px;}
#drag .title a.max{background-position:-60px 0;}
#drag .title a.max:hover{background-position:-60px -29px;}
#drag .title a.revert{background-position:-149px 0;display:none;}
#drag .title a.revert:hover{background-position:-149px -29px;}
#drag .title a.close{background-position:-89px 0;}
#drag .title a.close:hover{background-position:-89px -29px;}
#drag .content{overflow:auto;margin:0 5px;}
#drag .resizeBR{position:absolute;width:14px;height:14px;right:0;bottom:0;overflow:hidden;cursor:nw-resize;background:url(img/resize.png) no-repeat;}
#drag .resizeL,#drag .resizeT,#drag .resizeR,#drag .resizeB,#drag .resizeLT,#drag .resizeTR,#drag .resizeLB{position:absolute;background:#000;overflow:hidden;opacity:0;filter:alpha(opacity=0);}
#drag .resizeL,#drag .resizeR{top:0;width:5px;height:100%;cursor:w-resize;}
#drag .resizeR{right:0;}
#drag .resizeT,#drag .resizeB{width:100%;height:5px;cursor:n-resize;}
#drag .resizeT{top:0;}
#drag .resizeB{bottom:0;}
#drag .resizeLT,#drag .resizeTR,#drag .resizeLB{width:8px;height:8px;background:#FF0;}
#drag .resizeLT{top:0;left:0;cursor:nw-resize;}
#drag .resizeTR{top:0;right:0;cursor:ne-resize;}
#drag .resizeLB{left:0;bottom:0;cursor:ne-resize;}
</style>
<script type="text/javascript">
/*-------------------------- +
  获取id, class, tagName
 +-------------------------- */
var get = {
	byId: function(id) {
		return typeof id === "string" ? document.getElementById(id) : id
	},
	byClass: function(sClass, oParent) {
		var aClass = [];
		var reClass = new RegExp("(^| )" + sClass + "( |$)");
		var aElem = this.byTagName("*", oParent);
		for (var i = 0; i < aElem.length; i++) reClass.test(aElem[i].className) && aClass.push(aElem[i]);
		return aClass
	},
	byTagName: function(elem, obj) {
		return (obj || document).getElementsByTagName(elem)
	}
};
var dragMinWidth = 250;
var dragMinHeight = 124;
/*-------------------------- +
  拖拽函数
 +-------------------------- */
function drag(oDrag, handle)
{
	var disX = dixY = 0;
	var oMin = get.byClass("min", oDrag)[0];
	var oMax = get.byClass("max", oDrag)[0];
	var oRevert = get.byClass("revert", oDrag)[0];
	var oClose = get.byClass("close", oDrag)[0];
	handle = handle || oDrag;
	handle.style.cursor = "move";
	handle.onmousedown = function (event)
	{
		var event = event || window.event;
		disX = event.clientX - oDrag.offsetLeft;
		disY = event.clientY - oDrag.offsetTop;
		
		document.onmousemove = function (event)
		{
			var event = event || window.event;
			var iL = event.clientX - disX;
			var iT = event.clientY - disY;
			var maxL = document.documentElement.clientWidth - oDrag.offsetWidth;
			var maxT = document.documentElement.clientHeight - oDrag.offsetHeight;
			
			iL <= 0 && (iL = 0);
			iT <= 0 && (iT = 0);
			iL >= maxL && (iL = maxL);
			iT >= maxT && (iT = maxT);
			
			oDrag.style.left = iL + "px";
			oDrag.style.top = iT + "px";
			
			return false
		};
		
		document.onmouseup = function ()
		{
			document.onmousemove = null;
			document.onmouseup = null;
			this.releaseCapture && this.releaseCapture()
		};
		this.setCapture && this.setCapture();
		return false
	};	
	//最大化按钮
	oMax.onclick = function ()
	{
		oDrag.style.top = oDrag.style.left = 0;
		oDrag.style.width = document.documentElement.clientWidth - 2 + "px";
		oDrag.style.height = document.documentElement.clientHeight - 2 + "px";
		this.style.display = "none";
		oRevert.style.display = "block";
	};
	//还原按钮
	oRevert.onclick = function ()
	{		
		oDrag.style.width = dragMinWidth + "px";
		oDrag.style.height = dragMinHeight + "px";
		oDrag.style.left = (document.documentElement.clientWidth - oDrag.offsetWidth) / 2 + "px";
		oDrag.style.top = (document.documentElement.clientHeight - oDrag.offsetHeight) / 2 + "px";
		this.style.display = "none";
		oMax.style.display = "block";
	};
	//最小化按钮
	oMin.onclick = oClose.onclick = function ()
	{
		oDrag.style.display = "none";
		var oA = document.createElement("a");
		oA.className = "open";
		oA.href = "javascript:;";
		oA.title = "还原";
		document.body.appendChild(oA);
		oA.onclick = function ()
		{
			oDrag.style.display = "block";
			document.body.removeChild(this);
			this.onclick = null;
		};
	};
	//阻止冒泡
	oMin.onmousedown = oMax.onmousedown = oClose.onmousedown = function (event)
	{
		this.onfocus = function () {this.blur()};
		(event || window.event).cancelBubble = true	
	};
}
/*-------------------------- +
  改变大小函数
 +-------------------------- */
function resize(oParent, handle, isLeft, isTop, lockX, lockY)
{
	handle.onmousedown = function (event)
	{
		var event = event || window.event;
		var disX = event.clientX - handle.offsetLeft;
		var disY = event.clientY - handle.offsetTop;	
		var iParentTop = oParent.offsetTop;
		var iParentLeft = oParent.offsetLeft;
		var iParentWidth = oParent.offsetWidth;
		var iParentHeight = oParent.offsetHeight;
		
		document.onmousemove = function (event)
		{
			var event = event || window.event;
			
			var iL = event.clientX - disX;
			var iT = event.clientY - disY;
			var maxW = document.documentElement.clientWidth - oParent.offsetLeft - 2;
			var maxH = document.documentElement.clientHeight - oParent.offsetTop - 2;			
			var iW = isLeft ? iParentWidth - iL : handle.offsetWidth + iL;
			var iH = isTop ? iParentHeight - iT : handle.offsetHeight + iT;
			
			isLeft && (oParent.style.left = iParentLeft + iL + "px");
			isTop && (oParent.style.top = iParentTop + iT + "px");
			
			iW < dragMinWidth && (iW = dragMinWidth);
			iW > maxW && (iW = maxW);
			lockX || (oParent.style.width = iW + "px");
			
			iH < dragMinHeight && (iH = dragMinHeight);
			iH > maxH && (iH = maxH);
			lockY || (oParent.style.height = iH + "px");
			
			if((isLeft && iW == dragMinWidth) || (isTop && iH == dragMinHeight)) document.onmousemove = null;
			
			return false;	
		};
		document.onmouseup = function ()
		{
			document.onmousemove = null;
			document.onmouseup = null;
		};
		return false;
	}
};
window.onload = window.onresize = function ()
{
	var oDrag = document.getElementById("drag");
	var oTitle = get.byClass("title", oDrag)[0];
	var oL = get.byClass("resizeL", oDrag)[0];
	var oT = get.byClass("resizeT", oDrag)[0];
	var oR = get.byClass("resizeR", oDrag)[0];
	var oB = get.byClass("resizeB", oDrag)[0];
	var oLT = get.byClass("resizeLT", oDrag)[0];
	var oTR = get.byClass("resizeTR", oDrag)[0];
	var oBR = get.byClass("resizeBR", oDrag)[0];
	var oLB = get.byClass("resizeLB", oDrag)[0];
	
	drag(oDrag, oTitle);
	//四角
	resize(oDrag, oLT, true, true, false, false);
	resize(oDrag, oTR, false, true, false, false);
	resize(oDrag, oBR, false, false, false, false);
	resize(oDrag, oLB, true, false, false, false);
	//四边
	resize(oDrag, oL, true, false, false, true);
	resize(oDrag, oT, false, true, true, false);
	resize(oDrag, oR, false, false, false, true);
	resize(oDrag, oB, false, false, true, false);
	
	oDrag.style.left = (document.documentElement.clientWidth - oDrag.offsetWidth) / 2 + "px";
	oDrag.style.top = (document.documentElement.clientHeight - oDrag.offsetHeight) / 2 + "px";
}
</script>
</head>
<body>
<div id="drag" style="left: 661px; top: 131px; width: 733px; height: 549px;">
    <div class="title" style="cursor: move;">
        <h2>这是一个可以拖动的窗口</h2>
        <div>
            <a class="min" href="javascript:;" title="最小化"></a>
            <a class="max" href="javascript:;" title="最大化"></a>
            <a class="revert" href="javascript:;" title="还原"></a>
            <a class="close" href="javascript:;" title="关闭"></a>
        </div>
    </div>
    <div class="resizeL"></div>
    <div class="resizeT"></div>
    <div class="resizeR"></div>
    <div class="resizeB"></div>
    <div class="resizeLT"></div>
    <div class="resizeTR"></div>
    <div class="resizeBR"></div>
    <div class="resizeLB"></div>
    <div class="content">
        ① 窗口可以拖动；<br>
        ② 窗口可以通过八个方向改变大小；<br>
        ③ 窗口可以最小化、最大化、还原、关闭；<br>
        ④ 限制窗口最小宽度/高度。
    </div>    
</div>


</body></html>